An acceptance letter is not a legally binding document, nor is your deposit, nor is you showing up to orientation, buying your equipment and being in school for a month. If most schools found out at any point that you decided once you were accepted you could stop trying, your ass would be out of that school so fast... Every school asks for a final transcript, many because they require that you finish a degree and the only verifiable place for this is on an official final transcript, but also because they need to make sure you maintain your GPA and finish all your courses, especially the requisites. I think most schools would frown upon and question someone even if they already had their degree and dropped out of some bull$hit electives in the spring. You need to show commitment to academics if you expect them to teach you for four years.